In general, copy machines or laser printers perform copying or printing by using powder-type toner. Here, a cartridge in which a drum is coupled to a toner accommodation part is mainly used. Also, most of cartridges containing toner is consumable and disposable and has a high price because it is impossible to refill toner. Thus, when toner filled in a cartridge is exhausted, the cartridge should be replaced with a new cartridge. As a result, maintenance costs may be expensive, and waste of resources may be serious. Accordingly, there is a growing need of an automatic cartridge filling device that detects a residual quantity of toner without separating an active cartridge from a main body to automatically fill lacking toner.
In a toner refill device according to a related art, black and white toner is supplied merely by rotation of a rotation screw. Thus, the toner may not be smoothly supplied by the rotation screw, and it may be impossible to confirm residual quantity of toner within the cartridge. In addition, the toner may be excessively supplied or leaked. Also, in the toner refill device according to the related art, since it is difficult to confirm a charged state of a toner refill tank, the state of the toner refill tank should be frequently confirmed.
Also, Korean Patent No. 10-0980385, titled “Automatic Cartridge Toner Refiller of Laser Printer” which is disclosed by the present inventor has a limitation in which it is difficult to fill a tank 100% full of toner because the toner is filled by using only air.